Thermal and magnetic field stability of holmium single atom magnets

TL;DR

This study demonstrates that holmium atoms on magnesium oxide exhibit high coercivity and magnetic bistability at elevated temperatures, with potential implications for atomic-scale magnetic storage and quantum computing.

Contribution

It provides the first detailed measurements of magnetic stability and anisotropy in Ho single atom magnets at temperatures up to 45 K.

Findings

Ho atoms show coercive fields >8 T at 35 K

Magnetic bistability persists for minutes at 35 K

Spontaneous magnetization reversal observed at 45 K

Abstract

We use spin-polarized scanning tunneling microscopy to demonstrate that Ho atoms on magnesium oxide exhibit a coercive field of more than 8 T and magnetic bistability for many minutes, both at 35 K. The first spontaneous magnetization reversal events are recorded at 45 K for which the metastable state relaxes in an external field of 8 T. The transverse magnetic anisotropy energy is estimated from magnetic field and bias voltage dependent switching rates at 4.3 K. Our measurements constrain the possible ground state of Ho single atom magnets to either Jz = 7 or 8, both compatible with magnetic bistability at fields larger than 10 mT.